Audio speaker with back volume containing adsorptive material

Abstract

An audio speaker having a speaker housing surrounding a back volume that is divided into a rear cavity behind a speaker driver and an adsorption cavity separated from the rear cavity by a permeable partition, is disclosed. More particularly, the adsorption cavity may be defined between the speaker housing and the permeable partition, and may be directly filled with adsorptive particles to adsorb gas during sound generation. The permeable partition may allow the gas to flow between the rear cavity and the adsorption cavity, and may retain the adsorptive particles within the adsorption cavity. Other embodiments are also described and claimed.

Description

BACKGROUND[0001]1. Field[0002]Embodiments related to an audio speaker having a speaker housing surrounding a back volume that is divided into several cavities by a permeable partition, are disclosed. More particularly, an embodiment related to a multi-cavity back volume within a speaker housing, the multi-cavity back volume having a cavity defined between the speaker housing and a permeable partition, and that may be filled with an adsorptive material to adsorb gas during sound generation, is disclosed.[0003]2. Background Information[0004]A portable consumer electronics device, such as a mobile phone, a tablet computer, or a portable media device, typically includes a system enclosure surrounding internal system components, such as audio speakers. Such devices may have small form factors with limited internal space, and thus, the integrated audio speakers may be micro speakers, also known as microdrivers, that are miniaturized implementations of loudspeakers having a broad frequency...

AI Technical Summary

Benefits of technology

[0005]Portable consumer electronics devices, such as mobile phones, have continued to become more and more compact. As the form factor of such devices shrinks, system enclosures become smaller and the space available for speaker integration is reduced. More particularly, the space available for a speaker back volume decreases, and along with it, low frequency acoustic performance diminishes. However, as described below, the effective back volume of a portable consumer electronics device may be increased without increasing the actual physical size of the back volume. More particularly, an adsorbent material may be incorporated within the back volume to lower the frequency of the natural resonance peak and thereby make bass sounds louder. The adsorbent material may reduce the spring rate of the speaker by adsorbing and desorbing air molecules as pressure fluctuates within the back volume during sound generation. Such adsorption / desorption may increase system efficiency at lower frequencies to produce more audio power. Thus, the audio speaker may produce better sound in the same form factor, or produce equivalent sound in a smaller form factor. However, directly incorporating an adsorbent material within the back volume to improve acoustic performance may cause side effects. In particular, incorporating loose adsorbent particles directly within the back volume may create a system that is physically unbalanced and susceptible to damage as the particles shift, e.g., due to the mobile device being carried or moved by a user. Furthermore, attempting to mitigate these effects by packaging the adsorbent particles in a secondary enclosure, e.g., a mesh bag, that is then located in the back volume may cost precious enclosure space, as the secondary enclosure walls occupy vertical clearance in the back volume. Thus, for adsorbent materials to be used in a speaker back volume to enhance acoustic performance within the smallest possible form factor, an audio speaker having a speaker enclosure that physically isolates an adsorbent material from sensitive driver components without adding additional system thickness may be needed.

Problems solved by technology

Due to their small size, micro speakers tend to have limited space available for a back volume.

Furthermore, given that acoustic performance in the low frequency audio range usually correlates directly with the back volume size, micro speakers tend to have limited performance in the bass range.

More particularly, the space available for a speaker back volume decreases, and along with it, low frequency acoustic performance diminishes.

However, directly incorporating an adsorbent material within the back volume to improve acoustic performance may cause side effects.

In particular, incorporating loose adsorbent particles directly within the back volume may create a system that is physically unbalanced and susceptible to damage as the particles shift, e.g., due to the mobile device being carried or moved by a user.

Furthermore, attempting to mitigate these effects by packaging the adsorbent particles in a secondary enclosure, e.g., a mesh bag, that is then located in the back volume may cost precious enclosure space, as the secondary enclosure walls occupy vertical clearance in the back volume.

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